COLOMBO (AFP) - Some 48 Tamil Tiger rebels and seven soldiers were killed in ground battles across Sri Lanka's war-ravaged northern district, the defence ministry said Saturday. Troops fought fierce battles on Thursday and Friday, with the worst fighting reported in Vavuniya, where 27 rebels and three soldiers were killed, the ministry said. Sri Lanka fighter jets also carried out three air sorties over rebel areas in the north on Friday and Saturday, the airforce said. The Liberation Tigers of Tamil Eelam (LTTE) did not comment on the fighting, but accused the special army commandos of setting off a roadside mine inside rebel-territory on Friday, killing a civilian. The two days of fighting raised the number of rebels killed by troops to 5,673 since January, while 519 soldiers have died in combat during the same period, according to ministry figures. The government has poured a record 1.5 billion dollars into this year's war efforts and troops are now concentrating on dismantling the LTTE's de facto state in the north. In January Colombo pulled out of a Norwegian-brokered truce with the LTTE, saying it believed it had the upper hand in the long-running conflict that has claimed tens of thousands of lives since 1972.